Origin of Species Variorum

→ varied, and therefore less severe, 1872

severe 1859 1861 1866

varied and therefore less severe 1869

→ up, 1872

up the circumstances favourable and unfavourable to natural selection, 1859 1860 1861 1866

up the circumstances favourable and unfavourable for the production of new species through natural selection, 1869

→ permits, the circumstances favourable and unfavourable for the production of new species through natural selection. 1872

permits. 1859 1860 1861 1866 1869

→ OMIT 1861 1866 1869 1872

looking to the future, 1859 1860

→ will have been 1869 1872

and which consequently will exist for long periods in a broken condition, will be 1859

and which consequently will exist for long periods in a broken condition, is 1860

and which consequently has existed for long periods in a broken condition, has been 1861 1866

→ for a long time 1869 1872

long 1859 1860 1861 1866

→ OMIT 1869 1872

will first have 1859

first 1860 1861 1866

→ will have been 1869 1872

at this period 1859 1860 1861 1866

→ new species will have been 1869 1872

species will thus be 1859 1860

species will thus have been 1861 1866

→ have been very 1872

be 1859 1860

have been 1861 1866 1869

→ It can act only when there are 1872

Its action depends on there being 1859 1860 1861 1866

The result depends on there being 1869

→ natural polity of a district 1872

polity of nature, 1859 1860 1861 1866 1869

→ the 1872

some of the inhabitants of the country undergoing 1859 1860 1861

some of the inhabitants of the country under- going 1866

some of the inhabitants of the country under-going 1869

→ of its existing inhabitants. 1872

kind. 1859 1860 1861 1866 1869

↑ 1 blocks not present in 1872; present in 1859 1860 1861 1866 1869

The existence of such places will often depend on physical changes, which are generally very slow, and on the immigration of better adapted forms having been checked.

→ in some slight degree 1872

more or less 1869

→ it would often be long before 1872

OMIT 1869

→ in various parts of the organisation might 1872

better adapted to the then existing conditions, may not soon 1869

→ But 1869 1872

On the other hand, 1859 1860 1861 1866

confined area, and

thus

~~from~~

from

having

thus

....

been exposed to less →varied, and therefore less severe, competition.

To sum →up, as far as the extreme intricacy of the subject →permits, the circumstances favourable and unfavourable for the production of new species through natural selection. I

conclude,

conclude

→OMIT that for terrestrial productions a large continental area,

which,

which

will probably

has

undergo

undergone

many oscillations of level, →will have been the most favourable for the production of many new forms of life,

likely

fitted

to endure →for a long time and to spread widely.

For

Whilst

the area →OMIT existed as a continent,

and

....

the

inhabitants,

inhabitants

→will have been numerous in individuals and kinds,

will

and will

have been subjected to

very

....

severe competition. When converted by subsidence into large separate islands, there will still

exist

have existed

many individuals of the same species on each

island:

island;

intercrossing on the confines of the range of each →new species will have been

checked:

checked;

after physical changes of any kind, immigration will

be pre-

have been

vented,

prevented,

so that new places in the polity of each island will have

had to

be filled up by

modifications

the modification

of the old inhabitants; and time will

have been

allowed for the varieties in each to become well modified and perfected. When, by renewed elevation, the islands

shall be

were

re-converted

reconverted

into a continental area, there will again →have been very severe competition: the most favoured or improved varieties will

have been

enabled to spread: there will

have been

much extinction of the less improved forms, and the relative proportional numbers of the various inhabitants of the

renewed

reunited

continent will again

have been

changed; and again there will

have been

a fair field for natural selection to improve still further the inhabitants, and thus

produce

to produce

new species.

That natural selection

will always

always

~~generally~~

generally

act

acts

with extreme

slowness,

slowness

I fully admit. →It can act only when there are places in the →natural polity of a district which can be better

filled through

occupied by

→the

modifications

modification

of some →of its existing inhabitants. ↑ The occurrence of such places will often depend on physical changes, which generally take place very slowly, and on the immigration of better adapted forms being prevented. As some few of the old inhabitants become modified, the mutual relations of others will often be disturbed; and this will create new places, ready to be filled up by better adapted forms; but all this will take place very slowly. Although all the individuals of the same species differ →in some slight degree from each other, →it would often be long before differences of the right

nature,

nature

→in various parts of the organisation might occur. The

results

result

will

would

often be greatly retarded by free

inter-crossing.

intercrossing.

Many will exclaim that these several causes are amply sufficient

wholly

....

stop

neutralise

the

action

power

of natural selection. I do not believe so. →But I